Fluid distribution system



Jan. 31, 1939. c; R ALDEN 2,145,640

FLUID DISTRIBUTION SYSTEM Filed May 11, 1932 6 Sheets-Sheet l Invenfs/Cal/46H flaw/den Jan. 31, 1939.

C. R. ALDEN FLUID DISTRIBUTION SYSTEM Filed May 11, 1 932 I 6Sheets-Sheet 2 I 82 Z3 I a g a \74 I n f 2?:

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FLUID DISTRIBUTION SYSTEM Filed May 11, 1932 6 Sheets-Sheet 3 Jam 31,1939. c. R ALDEN 2,145,640

FLUID DISTRIBUTION SYSTEM Filed May 11, 1932 6 Sheets-Sheet 4 I .1 im/0.7 f5 I nveni-a/ Gui 16H v i/den Jan. 31, 1939. c. R. ALDEN FLUIDDTSTRIBU'PTON SYSTEM Filed May 11, 1932 6 Sheets-Sheet 5 Invmal 00% whenC R. ALDEN Jan. 31, 1939.

FLUID DISTRIBUTION SYSTEM Filed May 11, 1932 6 Sheets-Sheet 6 PatentedJan. 3i, 1939 UNlWED STATES PATENT @FFlCE Cell-O Corporation,

gall

a corporation of Michi- Application May 11, 1932, Serial N0. 610,612

3 Claims.

The present invention relates generally to fluid distribution systems,and more particularly to improvements in fuel admission or injectionsystems for internal combustion engines.

One of the objects of the present invention is to provide a novel fuelinjection system having a fuel injection nozzle, a fuel feed conduitconnected to the nozzle, a direct source of fuel under a relatively highpressure, a secondary source branching from said direct source andincluding pressure reducing means for maintaining a relatively lowpressure, and means selectively adjustable into position to connecteither of the sources periodically to the conduit.

Another object of theinvention is to provide a new and improved fuelinjection system having a plurality of nozzles and means for supplyingfuel under pressure to the nozzles for discharge therefrom, includingmeans for limiting the maximum amount of fuel that can be injected inany one period of injection.

A more specific'object is to provide a novel fuel injection systemhaving a plurality of injection nozzles, a single fuel fee-d conduitconnected in common to the nozzles and including a pressurestoragechargelirniting reservoir, a plurality of control conduits connectedrespectively to the nozzles, and means for periodically charging thefeed conduit for successively effecting pressure fluctuations in thecontrol conduits to effect sequential operation of the nozzles so as torelease fuel from the feed conduit.

Further objects and advantages will become apparent as the descriptionproceeds.

In the accompanying drawings, Figure 1 is a diagrammatic representationof a fluid injection system embodying the features of my invention, thenozzles for each cylinder being shown as constructed in a single unit.

Fig. 2 is an enlarged sectional view taken along line 2-2 of Fig. l ofthe multiple nozzle unit and holder.

Fig. 3 is a transverse sectional view taken along line 3'-3 of Fig. 2.

Fig. i is a fragmentary side view of the holder taken along line l--4 ofFig. 3.

Fig. 5 is an axial sectional view on an enlarged scale of the multiplenozzle unit.

Fig. 6 is a view of the unit with the plungers removed and taken alongbroken line 6--6 of Fig.

Fig. 7 is an axial sectional view taken along line 'l-'l of Fig. 6.

Fig. 8 is an enlarged axial sectional view of the distributor.

Figs. 9 to 14 are transverse sectional views of the distributor takenrespectively along lines 9-4) to I l-44 of Fi 8.

Fig. 15 is an axial sectional view of the distributor taken along linel5-l5 of Fig. 9.

Fig. 16 is a detail sectional view on an enlarged scale of the pressuresubdivider valve.

Fig. 17 is a fragmentary diagrammatic View of the distributor showing adevelopment of the distributor casing in cross-hatched outline super- 10imposed on a development of the rotor in dotted outline, with the rotoradjusted axially for full open throttle operation.

Fig. 18 is a view similar to Fig. 17 but with the rotor adjusted axiallyfor idling throttle opera ltl tion.

Fig. 19 is a time chart illustrating the timed relation of the openingof the respective nozzles for each cylinder to the crank shaft rotation.

Fig. 20 is a polar diagram comprising curves 2o illustrating thegraduated rate of fuel injection and the rate of pressure variation forone axial and phase setting of the distributor.

While the invention is susceptible of various modifications andalternative constructions, I 2n have shown in the drawings and willherein describe in detail the preferred embodiment, but it is to beunderstood that I do not thereby intend to limit the invention to thespecific form disclosed, but intend to cover all modifications and goalternative constructions falling within the spirit and scope of theinvention as expressed in the appended claims.

The engine Referring more particularly to the drawings, 35 the presentsystem of fluid distribution, although adapted for various uses andparticularly various types of internal combustion engines, is hereindisclosed for purposes of illustration as a liquid fuel injection systemapplied to 2. Diesel engine 40 having eight cylinders of which only oneis shown. Each engine cylinder comprises a cylinder body 9 closed at theouter end by a cylinder head Ill, and provided with suitable air inletand exhaust valves (not shown). A piston H is slid- 45 ably disposed inthe cylinder body 9, and is connected through a rod I2 to a crank shaftIll. The piston H is so related to the cylinder body 9 that at the endof the compression stroke, a high degree of compression will be obtainedin 50 the initially small combustion space M underlying the cylinderhead Ill.

The injection means Fuel is injected into the cylinders in timed sosequence, and in each each cylinder, the multiple nozzle groups for therespective cylinders being identified generally by the referencecharacters I to 8 inclusive. Preferably, the nozzle groups are'alike inconstruction h a choice in the "cylinder 9, as shown in 23, apertured atof the casing, engages the outer face of the and tion all.

arrangement, and hence a detailed descripof group 1 for the cylinder 9will sufiice for The multiple nozzle group 1 may comprise any desirednumber of injection nozzles, two nozzles, namely a primary nozzle I5 anda secondary nozzle I6, being shown in the present instance. Thesenozzles I5 and I6 may be mounted in any suitable position to dischargeinto the combustion space I4, and may be arranged separately,

but preferably they are combined in a unitary structure as shown inFigs. 5 and 6. The provision of a plurality of injection nozzles affordsdesign of the combustion chamber such that a uniform and thoroughpenetration of the combustion space I4 can be obtained without relyinglargely on turbulence. In the present instance, the nozzle unit I ismounted in the side of the Figs. I and 2, to inject a plurality ofjetsof fuel laterally into the combustion space I4. .With a plurality ofjets of fuel, quick, thorough and uniform penetration by the fuel of thecombustion space I4 and'flne atomization of the fuel are possible.

' The injection nozzles I5 and I6 of group 1 may be provided in variousforms. In the present instance, the unitary structure, of'whlch the twonozzles form part, comprises a cylindrical body I1 which is adapted tobe removably mounted in a holder I8 (Figs. 2 to 4).

In the preferred form, the holder I6 comprises ih shape, which has a.sleeve 20 of reduced diameter on its inner end, and which presents anannular peripheral seating shoulder 2 I at the juncture with the sleeve.7 The sleeve 20 is snugly disposed in the inner end of a bore 22 openingthrough a boss 23 on the side of the into the combustion space I4. Theouter portion of the bore 22 is enlarged as indicated at 24 to snuglyreceive the casing I9 and to provide an outwardly facing annular seat 25adapted for engagement by the shoulder 2|. A gasket washer 26 may bedisposed between'the shoulder 2| and the seat 25.

To secure the holder removably in position, the outer portion of thecasing I9 is formed with a peripheral flange 21, and is enlarged beyondthe flange as indicated at 28. A clamping plate to receive the outer end28 flange 21, and is securely clamped by means of bolts 3| threaded intothe end of the boss23.

The body I1 of the nozzle unit I is mounted in the sleeve 20-, and isformed adjacent its inner end with an annular peripheral seatingshoulder32 in engagement with an inner peripheral flange 33 on the inner end ofthe sleeve. A gasket washer 34 may be disposed between the shoulder 32and the flange 33. The outer end of the body I1 projects from the sleeve20 into the intermediate section of the casing Iain concentricallyspacedrelation thereto, and is formed with a peripheral end flange 35defining a central recess or chamber 36.

'The body I1 is held removably in position by means of a clamping rod 31extending. axially in arrangement of the nozzles and chamber 36constitutes cylinder 9 ing of the valves 54 differentials. Where fuelchamber, and the -reciprocable in parallel Since in the present instancewasher 39 is positioned between the flange 35' and the head 36. A clampnut 40 is adjustably threaded into the outer end 28v of the casing I9and has a centering recess 4I- engaging the outer end of the rod 31 tosecure the head 36 tightly against the body I1. A gasket washer 42 isdisposed between the rod 31xand the bottom of the recess 4|. The extremeouter end of the casing I9 is tightly closed by a screw plug 43. It willbe'evident that bodies I1 with different numbers of nozzles may bemounted interchangeably in the holder I8.

I5 and I6 (Figs. 5 to 7) respectively discharge tips 44 and 45 formed onthe inner end of the body I1 and having a plurality of jet orifices 46and 41 opening to the combustion space. The number, arrangement andsizes of the orifices 46 and 41 are subject to considerable selection,but in the present instance two'orifices 46 and four orifices 41, all ofthe same size, are shown. Two nozzle passages 48 and 49 respectively areformed in the tips 44 and 45 and communicate with the orifices 46 and41. The inner ends of the passages 48 and 49 open respectively pastconical valve seats 50 and 5| to two fuel chambers 52 and 53in the bodyI1. Valve members 54 and 55 are adapted to coact respectively with theseats 50 and EH to control the supply of fuelto the orifices 46 and 41.

The valves 54 and 55 are adapted to be opened or lifted by fuel pressurein the chambers'52 and 53, and to this end are carried by pressureresponsive members, such as reciprocable pistons or plungers 56 and 51.While within certain broad aspects of the'invention, provision may bemade for seating or closing the valves 54 and 55 under the influence ofany desired relative pressures applied through preferably thevalves areoperable fully hydrauli cally, and more specifically are seated byuniform fuel pressure acting on the outer ends of the plungers 56 and51. In the present instance, the a pressure chamber to which fuel underpressure is supplied, andin which the outer ends of both plungers 56 and51 are exposed. Y

' Selective operation of the valves 54 The nozzles comprise two and 55is nozzle I5 alone wi period and then both nozzles I5 and I6 will injectfuel over a final period. The successive openand 55in a predeterminedsequence is accomplished by subjecting the plungers 56 and 51"to unequallifting pressure equal seating pressures are employed, as illustrated,such differentials are obtained by exerting unequal net liftingpressures on theplungers 56 and 51 in the fuel chambers 52 and 53.

- Preferably, the valves 54 in parallel, so that the opening of one 'isnot physicallydependent on the opening of the; other, and are subject tothe same fuel pressure. Thus, the chambers 52 and 53 are joined by acommon fuel inlet passage 58 so as in effect to constitute one plungers56 and 51 are bores 59 and 60 formed in the body I1 and opening atopposite ends into the pressure and ffuelchambers 36 and'52, 53. bothplungers 56 and 51 are subjected in common to one seating fuel pressureand to one lifting fuel pressure, the unequal lifting pressuredifferentials are obany suitable medium,'

and 55 are arranged tained by making the ratio of the lifting pressurearea, exposed in the fuel chambers 52, 53, to the seating pressure area,exposed in the pressure chamber 36, for the plunger 56 greater than thatfor the plunger 51 when the valves 54 and 55 are seated. The specificarea ratios are determined by the design and dimensions of the plungers56 and 51 and the embraced areas ofthe valve seats 50 and 5!, and may beobtained in different ways by varying the relationship between theforegoing factors. In the form selected for illustration, the twoplungers 56 and 51 are cylindrical and of uniform diameter throughoutthe-"length of the bores 59 and 60, and differ onlysiightly in diameter,and the valve seat 50 is substantially smaller than the valve seat 5|.

It will be evident that when the valves 54 and 55 are open, the arearatios will be alike and equal to one, and when the valves are closed,the

lifting pressure areas will be reduced in effect by the areas of thevalve seats so that the area ratios will be unequal as described andless than one. Preferably, the effective cut-off areas of the valveseats 58 and 5| are twenty (20) and thirty (30) percent. of theassociated end faces of the respective plungers 56 and 51 so that thelatter have pressure area ratios of eighty (80) and seventy (70')percent. respectively when the valves 54 and 55 are seated.

To provide means for supplying fuel under pressure to the fuel chamber52, 53, the ends of the fuel inlet passage 58 intersect the inner endsof two diametrically opposed longitudinal slots 6| formed in theexterior of the nozzle unit body l1. The outer ends of the slots 6| opento the interior of the casing l9 about the rod 31, constituting a supplychamber 62.

Connected to the casing l9 and opening through a port 63 therein'to thechamber 62 is a fuel feed conduit 64. The connection preferablycomprises a sleeve 55 which is snugly positioned on the outer end 28 ofthe casing l9 and against the plate 29, and which has a lateral boss 66formed with an aperture 51 to receive the discharge end of theconduit'64. A clamp nut 68 is threaded into the aperture 61 against acollar 69 threaded onto the conduit 64 to secure the .end of the lattertightly against the casing IS in alinement with the port 63.

The conduit 64 is adapted to be connected to a suitable source of fuel,as hereinafter described, and is connected to all of the nozzle units lto 8. Thus, all of'the feed chambers 52, 53 are constantly inintercommunication through the common conduit or feed rail 64.

Fuel under pressure is adapted to be supplied to the pressure chamber 36through an axial passage or bore 10 formed in the rod 31. The outer endof the bore 10 opens through an alined axial bore 1| in the nut 46 tothe space 12 between the nut and the plug 43. A control conduit 13connected to the casing, IS in the same manner as the feed conduit 64opens to the space Similar control conduits 14 to 80 are providedrespectively for the other nozzle units 2 to 8, and all of the conduitsare adapted to be connected to a suitable source of fluid pressure, suchas liquid fuel pressure, as hereinafter described.

The connection for the conduit 13 comprises a second aperture BI in theboss 65, a collar 82 threaded onto the discharge end of the conduit, anda nut 83 threaded into the aperture against the collar to secure theconduit tightly against .the fuel lifting pressure'relativeiy above thefluid seating pressure, whatever the latter may be and however it may beapplied, to overcome the ratios. Opening of the valves 54 and 55 thusinvolves a reversal in direction of the pressure differential. In abroad sense, such reversal may be accomplished in various ways, as forexample by sufficiently increasing the pressure in the fuel chamber 52,53. Preferably, opening of the valves 54 and 55 is effected,subsequently to the establishment in the fuel chamber 52, 53 of thepressure, approximately equal to the normal pressure of the seatingfluid, at which the fuel is to be injected into the cylinder, bygradually reducing the seating pressure. As a result, no building up ofthe fuel pressure in the chamber 52, 53, involving a time consuming flowand a fluctuation in the injection pressure, nor creation of pressuresurges due to momentum, occur during opening of the valves. On thecontrary, the full injection pressure is immediately available, thusavoiding dribbling and providing a quick and sensitive control.

Since their seating area ratios are unequal, the valves 54 and 55 willopen in timed sequence upon reduction of the seating pressure. Therelationship of the control pressure reduction to the sequential openingof the valves 54 and 55 is illustrated in the time chart shown in Fig.19 wherein percentages of control pressure reduction are plottedalongthe ordinate, and time in degrees of crank shaft rotation isplotted along the abscissa. The rate of pressure reduction isrepresented by the curve w-b, assuming that 100 percent. represents thenormal maximum seating fuel pressure in the chamber 38, and that thefuel pressure in the chamber 52, 53 is equal thereto during opening ofthe valves 54 and 55, the drop in pressure starts at degrees of crankshaft rotation. After a drop in pressure of twenty (20) percent, theseating area ratio of .8 will have been overcome, and hence the valve 54will be opened at 0 degrees of crank shaft rotation. A further drop often percent. in the control pressure results in overcoming the seatingarea ratio of .7, and the consequent opening of the secondary valve 55at degrees of crank shaft rotation.

The multiple rate of fuel injection is illustrated diagrammatically inthe polar diagram of Fig. 20, in which the degrees of crank shaftrotation are indicated angularly, and the rate of injection is plottedalong the radians. Upon opening of the valve 54 at 0 degrees, i. e.,360-0 before top dead center, fuel is injected through the primarynozzle l5 at a rate c-d, depending on the injection pressure and. thecharacteristics of the valve 54 and the nozzle orifices 46. Subsequentopening of the valve 55 at degrees, i. e., 360.- before top dead center,causes fuel to be injected also through the secondary nozzle l6 at arate d-6, subject to the same factors as the rate Cd, thus injectingfuel at the combined rate c--e. Upon restoring the normal seatingpressure in the chamber 36, and reducing the fuel pressure in thechamber 52, 53, as through venting or injection after cut-off, thevalves 54 and 55 are both'quickly closed at p degrees after top mentialsteps approach to the rate curve.

The rate curve of injection is subject to adjustment so as toapproximate a theoretical ideal. i. e., to admit fuel into the enginecylinder 9 at the'most advantageous rate at any moment during the entireperiod of injection. Such adjustment can be accomplished by a judiciousvariation in the rate-of seating pressure drop and/or rise, and/orselection of diiferent seating area ratios for the valves 54 and 55,and/or selection of nozzles having different coeflicients of flow,and/orregulation of the relative extent of rise of the valves,Preferably, the valves 54 and 55 are opened in sequence and closedsubstantially simultaneously, although they may also be closed insequence. Ordinarily, therestriction to flow in the control conduits 13to 88, when being exhausted to a lower pressure, is such that a suitabletimed pressure drop to produce the desired rate curve is obtained.Varying the rate curve by changing the rate of control pressure drop maybe effected by adjusting the restriction to flow in the control tubes 13to 88 selectively in either or both directions.

The multiple nozzle means herein disclosed (see Figs. 2 to 7) forms thesubject matter of my di-' visional application Serial No. 131,771, filedMarch 19, 1937.

Pressure control means It will be noted that the'present system is ofthe hydraulic impulse type. As described, the injection of fuel into theengine cylinder 9 is determined in part by the shape of the rate curveis subject to adjustment, and which is responsive to the character ofthe hydraulic impulses. injection of fuel is also controlleddetermining 1) the phase relation of the injection period to the crankshaft rotation, i. e., the initial point of fuel introduction, (2) theduration of the injection period, and (3) the number of valves that maybe operated during the injection period. Preferably, a fluid pressuredistributor of the rotary type indicated generally at is employed.

The distributor 85 in its preferred form (see Figs. 8 to 15) comprises acylindrical casing 88 which is closed at one end by a removable screwplug 87!, and which is mounted at the other end on a housing 88 adaptedto be rigidly secured on the engine. A rotor 89 is slidably androtatably mounted in the casing 86, and has an extension shaft 98housing 88 for projecting therefrom through the operative connection tothe engine crank shaft I3. In the present instance, the

drive connection comprises a spiral gear 99 axially splined to the shaft90 and meshing with a. second spiral gear 92 on an idler shaft 93.. Thegear 92 meshes with a spiral gear 94 rigid with the shaft I3. The gearratio is such that the rotor 89 is driven at the necessary speedrelative to the crank shaft I3, i. e., one-half the crank shaft speedfor conventional four stroke cycle engines or at the crank shaft speedfor conventionaltwo stroke cycle engines.

The angular phase relation between the rotor 89 and the crank shaft I3is subject to adjustment through shifting of the gear 9I relative to thegear 92 longitudinally of the shaft 98. A hand actuator 95 isoperatively connected to the gear 9I, and thus affords manual means foreffecting the desired phase setting at will.

Any suitable means, such as an automatic governor (not shown) or amanual throttle actuator 96, may be provided for adjusting the rotor 89axially. In the present instance, the actuator 98 is operativelyconnected .to a gear sector 9'! pivoted on the housing 88-and meshingtherein with a sleeve rack 98 rotatably mounted on the shaft 98 foraxial movement therewith.

Opening. in spaced relation to the interior of the casing 86, andinterconnected by a longitudinal passage 99 formed therein, are threesubstantially alined high pressure fuel inlet ports I88, MI and I82. Ahigh pressure fuel line or conduit I83 is connected to the casing 86 inthe transverse plane (see Fig. 12) of the intermediate port IN, and isin communication therewith and with the passage 99.

The common branched fuel feed conduit 64, leading to the nozzle units Ito 8, is connected at its inlet end to the casing 88, and communicateswith the interior thereof through a port I 84. The ports I88 and I84 arelocated in transverse planes (see Figs. 18 and 11) closely spacedlongitudinally of the casing 88. Formed in the exterior of the rotor 89are eight uniformly peripherally spaced and narrow elongated feed slotsI85 to II 2, one slot for each nozzleunit. The slots are parallel to therotor axis; extend longitudinally throughthe transverse plane of thefeed port I 8k for all positions of axial adjustment of the rotor 89;are adapted to extend through the transverse. plane of the port I88 forthe purpose of periodically connecting the two ports to charge the feedconduit 84; and are connected respectively through radial passages II3to an axial cha ber II4 formed in the free end of the rotor 89/:nd henceconstantly in intercommunication.

Preferably, the ports I88 and I84 are spaced peripherally of the casing86, so that the periodic connection of the feed conduit 64 with the highpressure conduit I83 is established through successive sets of two ofthe slots, the associated passages II3 and the chamber H8.

Formed in the exterior of the rotor 89 is an uninterrupted peripheralhigh pressure belt defined by a groove II5 (see Figs. 8 and 12) inconstant communication with-the intermediate port I M for all positionsof axial adjustment. A cutoff land I I8 extends longitudinally of therotor 89 into one end and almost across the high pressure belt II 5.Formed in the side of the rotor 89 and extending longitudinally thereofis a narrow elongated low pressure slot ill. One end of the" slot II'lextends centrally into the land H8.

The eight control conduits 72 to 88 are suitably connected to the casing88, and open respectively through eight uniformly peripherally spacedcontrol ports H8 to I25 in a single transverse plane (see Fig. 13) tothe interior thereof in registration longitudinally of the rotor withthe high pressure belt H5 and the slot ill for all positions of-axialadjustment of the rotor.

. exterior of the rotor 89 in a single transverse plane (see Figs. 8 and14) and constantly in intercommunication through intersecting radialconnecting passages I34. Connected to the casing 86 and opening theretothrough a port I35 in the same plane as the high pressure port I02 (seeFig. 14) is a low pressure fluid conduit I36. The two ports are adaptedto communicate alternately and successively with the slots I26 to I33 inall axial positions of the rotor 89 so that each time the port I35 isover one of the slots I26 to I33, the slot III will be connected to thelow pressure conduit I36, and at alternate times the slot III isconnected to the high pressure conduit I03.

To vary the duration of pressure reduction in the control conduits 13 to80, and hence the period of injection, the slots I26 to I32 are inclinedto the rotor axis so that axial shifting of the rotor 69 is effective toadjust the phase relation of the period of communication of the slotswith the low pressure port I35 to the period of communication of theslot III with each of the control ports II8 to I25.

The operation is illustrated in Figs. 1'7 and 18. In Fig. 1'7, withthe'rotor 89 adjusted for full throttle opening and rotated intoposition about to effect operation of the multiple nozzle I, the highpressure port I00 has left the feed slot H2, and the feed port I04 hasleft the slot I06, so that the common feed conduit 64 has been chargedand out off preparatory for injection. The maximum fuel pressure is thusimpressed in the feed chamber 52, 53, but the valves 54 and 55 becauseof their differential seating area ratios remain closed.

The control port I I8 has left the high pressure belt I I5 and is aboutto communicate with the low pressure slot III preparatory for areduction of the seating pressure in the control conduit I3 and thechamber 36. Since the rotor 89 is adjusted for maximum throttle opening,the slot II! is connected to the low pressure substantially concurrentlywith communication with the port II8 so as to effect a seating pressurereduction of maximum duration for maximum injection. Thus, just as theport II8 is about to communicate with the slot III, the low pressureport I35 is about to communicate with the slot I26 and the high pressureport I02 is about to leave the slot I20.

Reduction of the seating pressure causes the valves 54 and 55. to openin predetermined sequence. Upon further rotation of the rotor 89, theport I35 will leave the slot I26 to interrupt the low pressureconnection, and the high pressure port I02 will come into communicationwith the slot I28 to charge the slot III with high pressure so as torestore the seating pressure in the chamber 36, thereby closing thevalves 54 and 55.

In Fig. 18, with the rotor 89 adjusted for idling throttle operation,and occupying the same rotary position as in Fig. 17, the angular phaserelation of the ports I00, I04 and II8 to the slots III, I05 and III isunaltered. However, the slot III upon communication with the port II8has already been connected for a substantial time to the low pressure,and hence the pressure port I35 will in a short time leave the slot I26so that the period of pressure reduction is of short duration. Thus, theperiod of pressure reduction is adjusted by varying the degree to whichthe communication of the slot III with the control port II8 overlaps theperiod of connection of the slot with the low pressure port I35. In thevariation of the duration of pressure reduction, the starting point ofpressure reduction is fixed while the cut-off is variable. It will beevident that if the rotor 89 is adjusted axially into a position whereinthe port I35 will have moved out of communication with the low pressuresource before the port II8 is brought into communication with the slot IIT, a closed throttle condition will exist and neither the primary valvenor secondary valve will open. It will be understood that at certainsmall throttle openings, the period of control pressure reduction may beso short that only the primary nozzle I5 will inject.

Provision is made for reducing the maximum charging pressure in the feedconduit 64 for idling operation, so as to insure quick and positiveseating of the nozzle valves and accurate metering of the small amountsof fuel injected. To this end, the feed slots I05 to I I2 are movableout of the range of the high pressure port I00 upon axial adjustment ofthe rotor 85 for small throttle openings (see Fig. 18) so as to preventcharging of the feed port I04 directly from the high pressure source,and means is provided for charging the feed port indirectly from thesource past a pressure reducing valve I31 (see Figs. 15, 17 and 18).

In the preferred form, the valve I3? is interposed between the chamberII4 and the high pressure belt II5. The chamber II4 opens past a valveseat I38 to a reduced axial bore extension I39 communicating through apassage I40 with the pressure belt II5. A valve member I4I having alongitudinally fluted guide stem I42 slidably disposed in the bore I39is normally urged against the seat I38 by a coiled compression springI43 in the chamber II4. The spring I43 is seated against an adjustingscrew plug I44 threaded into the chamber II4. The outer end of thechamber II4 is suitably closed by a removable screw plug I45. It will beevident that the pressure reduction effected by the valve I3'I on thefuel in passing from the belt II5 to the chamber II4 is subject toadjustment by adjusting the pressure of the spring I43.

The distributor 85 is constructed to prevent fuel oil from leaking pastthe ends of the rotor 89 out of the casing 86, and to lubricate andbalance the rotor so as to insure ease of rotation.

I Thus, two spaced annular labyrinth grooves I46 and I are formed ineach end of the casing 88 about the rotor 89. The inner grooves I46 andthe outer grooves I4'I are connected respectively by longitudinalpassages I48 and I49 formed in the wall of the casing 86 (see Fig. 15).A drain conduit I50 is connected to the casing 86 in communication withthe passage I48. It will be evident that fluid or fuel under pressuretending to leak outwardly along the rotor 89 will be caught by thegrooves I46 and withdrawn through the conduit I 50. A viscous fluidunder pressure, such for example as lubricating oil from the engine, issupplied to the outer grooves I47 through a.

conduit II connected to the casing 86 in communication with the passageI49, and tends to leak inwardly along the rotor 89 to the grooves I46so-as to insure the prevention of leakageof ,fuel outwardly past thegrooves I46, and to lubricate and balance. the rotor.

The fluid distributor herein disclosed (see Figs. 8 to 15) forms thesubject-matter of my divisional application Serial No. 179,070, filedDecember 10, 1937.

Charge limiting Within the broad aspects of'the invention, the.

feed conduit 64 may beconnected to the high pressure fuel source whileeach set of valves is open..

Preferably, however, the conduit 64 is charged with fuel at fullpressure, and then cut ofi or constitutes the discharge line of aconstant-presa reduced.

sealed before each pressure reduction inthe respective control conduits13 to 80. The trapped fuel is stored until'the nextnozzle unit in theorder of sequence is operated whereupon the fuel is injected under itsown pressure. It will be evident that in this manner the charge of fuelthat can be injected in any one period is definitely,

limited. Hence, an excessive overcharge cannot occur even though theengine speed is: greatly To increase the pressure capacity of the feedconduit 64 so as to cause the injection of fuel normally to occur undera substantially constant pressure, a storage reservoir I52 isinterposed'in the conduit. Preferably, the reservoir I52 consists of abottle or bulb having .a yieldable wall. The inherent resiliency ofthewalls of the conduit 64 and the reservoir I52 serves. to maintain thefuel pressureover a substantial period during injection. Theconduit 64with the reservoir thus constitutes a fuel pressure storage and chargelimiting means.

Pressure sources The high pressure conduit I03 may'be connected toanysuitable source of fuel under pressure. In the present instance, theconduit I03 cent. of the full seating pressure, say for example sixty(60)" percent. In .maintaining the relative pressure 'in the conduit I36as high as possible, the range of pressure fluctuations in the controlconduits I3 to 80 is kept to a minimum so' that an excess of fuel is notbled from the system in reducing the control pressure, and that-thefullpressure can be quickly restored. Thus, the nozzle valves are subject toa sensitive control, and can be operated at a high speed consistent withpresent day maximum engine speed requirements.

The conduit I36 preferably is connected to the fuel source, namely thepump I53, as for example through a subdivided valve I54 and a conduitI55'branching from the high pressure conduit I03.

The valve I54 may be of any suitable form adapted to maintain asubdivided fuel pressure in the conduit I36 of a substantially constantratio to the fuel pressure from the source, i. e., the pressure in theconduit I03. In its preferred form, the subdivider valve I54 (see Fig.16) comprises a casing I56 formed with a differential bore I5'I, ofwhich the large end is connected to the conduit I36 and the small end isconnected to the branch conduit I55. The differential area of the .boreI51 is equal in percentage to the pressure reduction that is to beeffected in the control conduits I3 to 80. Slidably disposed in the boreI5! is a differential piston I58 divided into two sections of differentdiameters.

The small section of the bore I51 is formed with an annular port I59which is connected through a by-pass passage I60 to the outer end ofthelarge section of the bore, and which is adapted to be uncovered by theouter end of the small section of the piston I58 upon a reduction of thepressure in the conduit I36 below the predetermined point determined bythe differential area so as to permit make-up fuel to pass from-theconduit I55 to the conduit I36. The large section of the bore I 51 isformed with an annular port I6I opening to a drain passage I62preferably connected to. the source of fuel supply. A peripheral grooveI63 is formed in the large section of the piston I58, and is connectedthrough an axial passage I64 to the large end of the bore I51. Upon anincrease in pressure in the conduit I36 above the predeterminedpressure, the groove I63 will be moved into communication with the portI6I- to bleed the excess fuel to the drain passage I 62. Thus, apressure bearing a substantial ratio to the pressure in the conduit I03is maintained in the conduit Rsum of operation Assuming that the ;nozzleunits I to 8 have the desired rate curve of injection, and that the gear9| has been adjusted axially to obtain the desired phase relation of theinjection periods to the cyclic movements of the pistons, the rotor 89is driven in timed relation to the crank shaft I3 to periodicallychargethe common feed conduit 64 and the accumulator I 52 at the full fuelpressure, and once for each fuel charge to reduce for a definitevariable period and then restore the seating pressure successively inthe respective control conduits I3 to 80, thus causing sequentialoperation of the nozzle units. The period ofpressure reduction and hencethe duration of injection are subject to adjustment, in accordance withthe engine requirements, by shifting the rotor 89, axially. At lowloads, the feed conduit 64 is charged at a pressure less than fullpressure to insure quick and accurate closing of the nozzle valves 54and 55. Preferably, the feed conduit 64 is cut off from the fuel sourceduring injection so that the maximum possible volume of fuel injected ina single charge is limited by the pressure and capacity characteristicsof the feed conduit and the storage reservoir I52.

The extent and rate of combustion pressure,

rise are limited and controlled to avoid combustion knock and excessivepeak pressures, and the attendant faults-such as noise, shock andfatigue and failure of the engine parts. Thus, the start of injection isdelayed until the compression temperature is most propitious forignition with a minimum of ignition lag. If fuel is injected too far inadvance of top dead center, even though the rate be decreased, thetemperature and presure in the combustion space will not have risenufficiently to insure prompt ignition, and hence ;here will be asubstantial ignition lag resulting n the accumulationof unburned fueland upon ltimate ignition in an objectionable knock. The hape of thecurve rate of injection should be uch that at the start only a smallamount of fuel s injected so that a minimum of heat is required oeifectignition. Thus, the initial fuel instead of cooling the air in thecompression space of he engine cylinder and thereby retarding igniion,burns quickly, thus increasing the combusion temperature and preparingthe combustion space for the ignition of the main part of the chargepractically at the rate at which it is introduced. The first fuel to beinjected, being under the full injection pressure is atomized at leastas finely as the main portion of the charge. By reason of the foregoingcontrol, the degree of pressure rise, depending on the amount of fuelburned before top dead center, and the rate of pressure rise, governedby the amount of fuel introduced before ignition are so regulated thatthe engine operates smoothly, noiselessly and efficiently.

I claim as my invention:

1. In a fuel injection system, in combination, an injection nozzle, afuel feed conduit connected to said nozzle, a direct source'of fuelunder a relatively high pressure, a secondary source branching from saiddirect source and including pressure reducing means for maintaining arelatively low pressure, and means selectively adjustable into positionto connect either of said sources periodically to said conduit.

2. In a fuel injection system, in combination, a plurality of injectionnozzles each having a pressure responsive valve actuator, a. single fuelfeed conduit connected in common to said nozzles at one side of saidactuators, said conduit having a pressure-storage charge-limitingreservoir, a plurality of control conduits connected to said nozzles atthe other side of said actuators, and means for periodically chargingand sealing said feed conduit and for successively effecting pres surefluctuations in said control conduits to cause said actuators to lift insequence so as to release fuel from said feed conduit.

3. In a fuel feeding system for a multiple cylinder internal combustionengine, in combination, a plurality of fluid pressure operable fuelinjection valves, one for each engine cylinder, each injection valvehaving a reciprocable valve member with lifting and seating areas atopposite ends thereof, a plurality of control lines, one for eachinjection valve, having control ports at one end and opening to saidseating areas of the respective injection valves at the other end, acommon feed line in constant open communication with the lifting areasof each of said injection valves and having a single control port, apressure-storage charge-limiting reservoir in said feed line, a sourceof fluid under relatively high pressure, a source of fluid underrelatively low pressure and means for periodically connecting saidsingle control port with said source of high pressure for predeterminedperiod to charge said common feed line and then alternately connect acontrol port of a selected control line in a predetermined order to saidsource of relatively low pressure to vent the pressure from the seatingarea of the associated injection valve, whereby .said valves are openedand closed for a predetermined time and in a predetermined order.

CARROIL R. ALDEN.

CERTIFICATE OF GORRECTI ON Patent No. 2,1l 5,6l 0.,

January 51, 1959 CARROLL R. ALDEN It is hereby certified that errorappears in the printed specification of the above numbered patentrequiring correctionas follows: Page 5, first column, line 2, for theword "chambers" read chamber; and second column,

line 67 for "j 60." read 560;

page LL, second column, line 68, for the numeral "72" read 75, page 5,first column, line 29, for "152" read 155; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 21st day of March, A. D. 1939.

(Seal) Henry Van Arsdale.

Acting Commissioner of Patents,

